How to Troubleshoot Kubuntu/KDE

[John Scott]

I've got a weird problem. I installed the standard Ubuntu 12.04 but then 
later installed kde with 'apt-get install plasma-desktop.' This worked 
great. About a week ago I saw the notification that there was a new 
version of Kubuntu available and so I clicked upgrade after my security 
updates had run. This upgraded me to 13.04 but now KDE can't complete 
loading. After logging in I get crash notifications after the initial 
loading screen that shows the start up graphic.

Essentially, after Xorg loads and login completes KDE errors out trying 
to load my session. All I have left is a black screen. Fortunately, I 
had Docky loading in my old setup and it still loads. When I click on a 
file manager icon that's pinned on Docky, my desktop loads with 
background and icons but I still don't get the K panel and launcher so 
there is no way except alt-F2 or Docky to launch anything and no way to 
log off.

I'd rather not reinstall if I don't have to because it's a headache and 
I've got home dir encryption, which might be a pain. Can anyone provide 
any suggestion as to what may have gone wrong with the upgrade or what 
might be disconnected that keeps my session from loading? I've tried 
renaming the .kde under /home/user to see if reinitializing will help 
but it doesn't. There must be other files at play that I don't know about.

Gnome and Unity still work.

John Scott